Expanding mandrel



F. M. B. FENNIMORE. EXPANDING MANDHEL. APPLICATION mm DEC.8, 192:.

1,433,992, Patented Oct. 31, 1922.

Patented Oct. 31, 1922.

UNITED STATES PATENT OFFICE.

FRANK M. B. FENNIMORE, OF BURLINGTON, NEW JERSEY, ASSIGNOIR TO UNITED STATES CAST IRON PIPE & FOUNDRY COMPANY, OF BURLINGTON, NEW JERSEY,

A CORPORATION OF NEW JERSEY.

' EXPANDING MANDREL.

Application filed December 8, 1921.

T 0 all w ham it may concern Be it known that I, FRANK M. B. Fnxm- MORE, a citizen of the United States of America, and resident of Burlington, in the county of Burlington, in the State of New Jersey, have invented certain new and useful Improvements in Expanding Mandrels, of which the following is a true and exact description, reference being had to the accompanying drawings, which form a part thereof.

My invention relates to expanding mandrels and is particularly, though not exclusively, designed for use in connection with mechanism used for cutting off ends of cast iron pipes. The object of my lnvention is to provide improved means for retracting the jaws of the mandrel and a further object of my invention is to so construct the aw retracting mechanism that it can be readily shifted to disengage the jaws and permit their removal and replacement and ready re-engagement with the retracting mechanism.

The nature of myimprovements will be best understood as described in connection with the drawings in which they are illustrated and in which Figure 1 is a sectional elevation taken through the center of the mandrel, and

Figure 2 a cross section on the line 22 of Fig. 1. v

A indicates the stem and B the head of the mandrel. Extending through the stem and into the head of the mandrel is the guideway 0 opening into an enlarged chamber indicated at D. E, E, etc. are radial openings or borings for the jaws of the mandrel, these extending through the head into the guide-way C. F is the wedge piece longitudinally movable in the gulde-way C and having inclined surfaces or wedges F one of such wedge surfaces lying beneath and registering with each of the borings E. F is a perforation formed in the end of the wedge piece and opening into an en- .larged chamber indicated at F G is a pin longitudinally movable in the perforation F having at its outer end a bearing head G which is normally pressed outward by the spring H resting in the large chamber F I is an actuating rod secured to the end of the wedge piece and through it the wedge piece is moved backward and forward in its Serial No. ,2O,832.

which fits in the end of the chamber D and in which are formed the bearings indicated at K K etc. for the pivot pins of the lever. K indicates a slot formed in the portion K and K a chamber also formed in this port-ion, of the head K for purposes to be described. L, L, etc. indicate pivot pins inserted in the bearings K and on which are pivoted the bent levers M, M, etc. having arms M which normally extend into the notches J of the jaws, as shown, and arms M which lie in contact with the head G of the pin G. These lever arms are also formed with shoulders indicated at M which by coming in contact with the stop surfaces K, see Fig. 1, arevent the ends M of the levers from moving too far downward to engage the notches J ofthe gripping jaws.

N is a. latch pin slidably moving in the chamber K and thrust outward by a spring N. This latch pin in its outward position engages a bushing N and a perforation N formed through the head B. O is a limit stop formed on the end of a screw 0 which is engaged by a threaded portion of an opening O in the head B, this limit stop extending into the slot K P indicates the face plate of a lathe in which, as shown, the mandrel stem is secured by bolts P. Q indicates a detachable annular extension of the mandrel head formed with bearings Q, which, when the ring is in position, register with the bearings E and through which the jaws extend. Ring extensions of different size can be used in connection with the mandrel head and in connection with gripping jaws of different lengths.

It will be obvious that when the wedge piece F is moved toward the right the wedge surface F acting on the inclined surfaces J of the jaws d will thrust the jaws outward and that as the aws move outward the levers M will turn freely to permit this outward movement since the wedge piece is moving toward the right which enables the ends M of the levers M to move also toward the right. When the wedge piece is moved toward the left this movement communicates through the spring H and head G and thrust against the ends M of the levers M moving the ends M downward and these lever ends M draw the jaws J inward as rapidly as the wedged surfaces on the wedge piece permit.

When it is desired to remove and replace the wedge pieces J the latch N is pushed inward and the head K moved outward to a distance permitted by the length of the slot K This movement withdraws the lever ends 1 from the notches J and permits the ready removal of the jaws, new jaws having been inserted in the radial bearings E, the head K is moved inward so as to engage the lever ends M with the notches in the 'aws.

aving now described my invention, what I claim as new and desire to secure by Let ters Patent, is:

1. An expanding mandrel having a head formed with a central bearing for a wedge piece, an enlarged chamber extending be yond said bearing and radial openings extending from the wedge piece bearing, in combination with a wedge piece longitudinally movable in the central bearing of the head, jaws radially movable in the radial openings of the head contacting with the wedge piece and jaw retracting levers located in the enlarged chamber of the head and actuated by the wedge piece in the lon gitudinal movement to release the jaws.

2. An expanding mandrel having a head formed with a central bearing for a wedge piece, an enlarged chamber extending beyond said bearing and radial openings extending from the wedge piece bearing, in

combination with a wedge piece longitudinally movable in the central bearing of the head, jaws radially movable in the radial openings of the head contacting with the wedge piece, jaw retracting levers located in the enlarged chamber of the head and a spring supported contact for actuating the levers of which the spring is put under compression by the wedge piece as it moves to release the jaws.

3. An expanding mandrel having a head formed with a central bearing for a wedge piece,'an enlarged chamber extending beyond said bearing and radial openings ex tending from the wedge piece bearing, in combination with a wedge piece longitudinally movable in the central hearing of the head, jaws radially movable in the radial openings of the head contacting with the wedge piece, a lever supporting head longitudinally movable in the enlarged chamber of the mandrel head and jaw retracting levers pivoted on the lever supporting head and formed to engage the jaws and lie in operative relation to the wedge piece when said head is in its inner position.

a. An expanding mandrel having a head formed with a central bearing for a wedge piece, an enlarged chamber extending beyond said bearing and radial openings extending from the wedge piece bearing, in combination with a wedge piece longitudinally movable in the central bearing of the head, jaws radially movable in the radial openings of the head contacting with the wedge piece, a lever supporting head longitudinally movable in the enlarged chamber of the mandrel head, means for securing said head in its inner position and jaw retracting levers pivoted on the lever supporting head and formed to engage the jaws and lie in operative relation to the wedge piece when said head is in its inner position.

FRANK M. B. FENNIMORE. 

